1. Field of the Invention
The invention relates to a terminal fitting.
2. Description of the Related Art
Japanese Unexamined Patent Publication No. 2003-317817 discloses technology using an aluminum conductor instead of a conventional conductor made of copper alloy for a lighter wire in a connecting structure for a terminal fitting and a wire.
Japanese Unexamined Patent Publication No. 2005-222815 discloses a terminal fitting in which a substantially rear half thereof is a wire crimping portion in the form of open barrels. A front end region of the wire crimping portion defines a wire barrel to be crimped into connection with a conductor of a wire, and a rear end region thereof defines an insulation barrel to be crimped into connection with an insulated part of the wire. The conductor is a twisted wire formed by twisting plurality thin metal wires and a front end portion of the conductor projects forward from the front end of the wire barrel.
Japanese Unexamined Patent Publication No. 2004-303526 discloses a terminal fitting with connecting portion to be connected with a mating terminal and a wire barrel behind the connecting portion. The wire barrel has two crimping pieces to be crimped into connection with a core exposed at the end portion of the wire and at a position so that the leading end of the core projects forward from the crimping pieces to be connected entirely with the core.
The crimp height of the above-described terminal fitting may be set low to avoid interference with a retainer or the like. However, the thin twisted conductive wires of the conductor then are loosened up before the wire barrel portion due to the tightening strength to the wire barrel portion and the leading ends of the thin loosened metal wires are deformed to be widened. If this occurs, the thin metal wires deformed to widen may interfere with the retainer.
Measures must be taken when using the aluminum conductor for a lighter wire or the like, as disclosed in Japanese Unexamined Patent Publication No. 2003-317817, to prevent an increase of contact resistance due to the difficulty of removing an oxide film of the aluminum conductor as compared with a copper conductor or other reason. One of these measures is to crimp the wire barrel more strongly into connection with the conductor. However, a stronger crimping of the wire barrel into connection with the conductor widens the leading end of the conductor more notably and there has been a demand for elaboration to prevent this.
The invention is developed in view of the above situation and an object thereof is to prevent a leading end portion of a conductor from being widened.